Innovative Design Labs (IDL) proposes to develop and deploy a low-cost measurement system which tracks exercise compliance and enables remote health coaching for patients with low back pain. Back pain is the most common cause of activity limitation in individuals younger than 45 years and is the second leading cause of disability in the U.S. afflicting between 70% and 85% of the population. It is the leading cause of lost wages and accounts for more than 700,000 surgical procedures per year with a total over $80 billion annually spent on treatment and care. Dynamic motion of the lumbar spine has been shown to change with disc degeneration and pain. Furthermore, these aberrant motion patterns can be improved with prescribed physical therapy and exercise. In practice, therapists qualitatively monitor back pain treatments through series of guided exercises and stretches in the clinic and then prescribe a protocol of exercises and stretches to be performed in the home. It is difficult to track performance and compliance over long periods of treatment. This research program aims to enable the long term treatment-tracking of patients with chronic low back pain. A novel, low-cost, highly accurate system that tracks and encourages compliance with a patients exercise protocol will be developed in phase II. Hypothesis: We hypothesize that a device which measures compliance to physical therapy regimens will increase patient participation. Specific Aims: 1) Develop a production-ready prototype hardware system; 2) Design and implement easy-to-use, cloud-enabled software for patients and health coaches; and 3) Conduct a human study to evaluate the effect of the system on compliance and quality of life.